Automatic presser-foot mechanism for leather-stitching machines



c. F. MILLER. AUTOMATIC PRESSER FOOT MECHANISM FOR LEATHER STITCHINGMACHINES. APPLICATION FIEED MAR. 16. 1921. 1

1&3 TATWQ Patented Oct. W, 1922;

2 SHEETS-SHEET 1.

W @w emw I attozmmq C. F. MILLER. AUTOMATIC PRESSER FOOT MECHANISM FORLEATHER STITCHING wmcmwss,

. APPLICATION FILED MARI-5,1921. 11 4811 7 Plififlilfid 001;. ML N22.

2 SHEETS-SHEET 2.

Patented llet, 1W, ,l

i l W ltd T lhi 4% CHARLES F. MILLER, OF CHICAGO,

ILLINOTS, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, T orrrcne'o srronMACHINERY corvrrnnv, or cmcee irmr' N OIS, A CORPORATION OF ILLINOIS.

Application filed March 16. 1921. Serial no. 452,676.

7 '0 all whom it may concern: 1

Be it known that l, CHAnL'ns F. MILLER,

a citizen of the United States, residing at Chicago, inthe county ofCook and State of Illinois, have invented it certain new and usefulImprovements in Automatic Presser- Foot Mechanism for Leather-StitchingMachines, of which the following is a specification.

This invention relates to new and useful improvements in wax threadleather stitching machines generally, but more specifically to anautomatic presser foot mechanism therefor.

One of the principal objects of the invention is to provide a presserfoot with means for automatically locking the same against movementduring the greater portion of a cycle and for releasing said lockingmeans during the lesserportionof the cycle, whereby the work will befirmly clamped against thG'WOIk support by the presser foot during thepenetrating movement of the awl, and whereby said presser foot will bereleased during the work-feeding strokev of the awl.

Another object of the invention is to provide manual means for releasingsaid locking means and raising the presser foot at any time during thecycle, whereby the work may be inserted or withdrawn.

Another object of the invention is to provide a cam-controlled mechanismfor intermittently actuating the locking mechanism.

to provide a locking mechanism and a cooperating manual means forreleasing this locking mechanism.

In the drawings,

Figure 1 is a side elevation showing my improved resser foot mechanism,

Figure 2 is a detail elevation with the adjustable disk removed,

Figure 3 is a rear view of the adj ustable disk, i i

Figure 1 is a detail sectional. view taken on theline it-4c of Figure 2,

Figure 5 is a view similar to Figure 1, but showing the manual meansshifted to release the locking mechanism. p y

i Like reference numerals designate corresponding parts in all thefiguresof the drawings.

Referri g to the fired a cam 6, having formed therein.

'19 of the machine, andcarries at its up roller-carrying lever 17 at Astill further object of the invention is drawings, 5 designates the mainshaft of the machine, on which is a peripheral notch 7 Disposed inspaced relation to the cam 6 1s a work support 8' on which the work 9 isadapted to be clamped by a presserfoot 10. This presser foot is in theform of an arm fulcrumed on a shaft 11, the center of the shaft beingindicated at 12. Fixed on the. shaft 11 is a brake lever 13, havingaconvexed outer end 1 1, which is adapted to cooperatewith the concavedface 15 of a brake shoe 16. A roller carrying lever 17 is pivoted at itslower end, as at 18, to the frame er end a roller 20whichis adaptedtoalternatiily engage the concentric portion 21 of the cam disk 6 and thenotch 7 thereof. The lever 17 is pivoted between the cam disk 6 and thebrake shoe l6 and is movable in a direction towards and fromsaidbrakeshoe. A link 22 has one end pivoted, as at 23, to the a pointabove the pivot 18 thereof, and has its otherend.

connected to the brake shoe 16 by a pivot pin 24;. y

From the above, it will be seen that when the roller 20 rides into thenotch 7 the lever 17 will be moved to the left, 'and,-con sequently, thelink 22 and the brake shoe 16 will be bodily moved in the same direc'tion, thus withdrawing the brake shoe from cooperative relation with theconvexed brake surface 14 of the presser foot lever 18.

When the presser footis in. its co-opera tive position, the pivot 24will be below a straight line drawn through the pivot 23 and the center12 of the presser foot sup porting shaft 11. This, in effect,constitutes a toggle link, so that any upward movement of the pivot 24will necessarily clamp the brake shoe 16 against the pi'esser foot lever13, andtherebylock said. presser foot '10 against movement. 1 When,however, the

roller 20 rides into the-notch 7, as above described, the pivot 24 andbrake shoe 16 will be moved towards the left and out of contact with thepresser foot lever 13, therepresser foot locking mechanism, I haveprovided a manually operable hand lever 25,

which is provided at its lower end with a head 26. The head 26 is, inturn, journaled on a boss 27 formed. on the "frame 15). The head 26 isprovided in its outer face with a circular seat 28, which iseccentrically arranged with respect to the pivot boss Formed on theinner face of the seat 1s a series of outwardly projecting and radiallydisposed ribs 29, which co-operate with a series 0']? radially disposedribs 30 formed on the inner face of a disk 31. The head 26 is held onthe boss 2'7 by means of a screw 32, and the disk 31 is held in positionby a screw p The ribs 29 and 30 cooperate to retain the disk 31 againstmove ment relative to the operating lever 25. These ribs, however,permit the disk 31 to be axially adjusted and retained in an adjustedposition. A link 34 has its upper end pivoted, as at 35, to the disk 31,and has its lower end fulcrumed on the pivot 24.

A locking pawl 36 passes through a suitable opening formed in the head26 and is adapted to engage a notch 37 formed in the periphery of theboss 27, and thereby lock the operating lever 25 in its normal orinoperative position. The pawl 36 is connected by a link 38 to a handlever 39, which is, in turn, pivoted, as at 40, to the operating lever25. A spring 41 is disposed between the main lever 25 and the hand lever39, and serves to retain the latter in its normal position.

. Fixed to the head 26 of the operating lever 25 is an arm 42 having acam-shaped nose 43 adapted to engage a forwardly extending pin 14, whichis fixed to the presser foot lever 13.

A spring 45 has its lower end connected to the presser foot lever 13 bya screw 16 and has its upper end connected to the frame of the machineby a screw 47. This spring normally exerts an upward pull on the presserfoot lever 13, and tends to yieldingly hold the presser foot 10 inengagement with the Work 9.

\Vhen it is desired to release the locking mechanism and raise thepresser foot 10 from off the work, the hand lever 1S drawn towards theoperating lever 25 to release the pawl 36 from its engagement with theboss 27. Continued movement of the operating lever 25 in the samegeneral direction, that is, towards the right, will cause the cam-shapednose 43 to be moved downwardly and into engagement with the pin 1 1.This movement will also move the pivot of the link 3% and thereby causethe pivot 21 to. bemoved further below a line passing through the pivot23 and the center of the presser foot supporting shaft '11. Uponcontinued movement of the operating lever 25, the presser foot lever 13will he swung around the shaft 11, thereby rais- Figure 5 of thedrawings. When it is dcsired to return the parts to their normal orlocked positions, the operator merely pushes the operating lever to itsinitial position, shown in l igure 1. This umvcmeut returns the brakeshoe 16 into coauurralivc locking engagement with the presser toot lever13 and also permits the locking pawl 36 to be seated in the retainingnotch 37. thus |ocl ing the presser toot against movement.

Inasmuch as the concentric surtace 21 ot the cam 6 is considerablylonger than the notch '7, the presser foot will be held in its lockedposition for the greater portion of each cycle, and will be releasedduring the smaller portion of each cycle.

By axially adjusting the disk 31, the link 34 and pivot 24 will bebodily shilted towards or from a line extending through the center 12and the pivot 23. thereby varying the efl ective positions of the brakelever 3 and the brake shoe 16.

Another important feature of my invention, resides in the peculiarconstruction ot the presser-foot per so, which, by relcrencc to Fig. 1of the drawings, it will. be seen is provided on one of its sides with apair of spaced and laterally extended arms or projections 48 and 49. Thespace between these arms is for the reception and operation of thecurved needle ot the machine as it oscillates.

By thus constructing the prcsscr-hmt the needle will be shielded fromthe uppers ot the shoes while the sewing is being done thereon, thusprcventing the said uppers getting in the way ot or being pierced by theneedle, and besides, this arrangement permits the stitching of the solesto be per formed when the shoe is presented upside down to the worksupport or when presented in the reverse manner.

\Vhat I claim is:

1. In a leather stitching machinc the combination with a work support,of a. pivoted presser toot co-operating thcrcwith, a brake-lever fixedto said toot.cam-controllcd means including a intake-shoe l'ricthmallyco-operating with said brake-lever tor locking the toot against pivotalmovements (lur ing the greater JOl'tiUll of each cycle and .lorreleasing said locking means durim:

the lesser portion ol each cycle. and means for, varying the position oisaid shoe with respect to said brake-lover.

2.111 a leather stitching machine, the combination with a work support,o t a pivoted presser foot co-operating therewith, a brake-lever fixedto said foot, a cam, means controlled by the cam including a.link-supported brake-shoe frictionally cooperating with said brake-leverfor look ing the foot against pivotal movements during the greaterportion of each cycle and,

ing-the presserfoot 10, as clearly shown in for releasing said lockingmeans during the iasiavo oted presser foot co-operating therewith,

a brake-lever fixed to said foot, a cam, a

lever fulcrumed on a fixed pivot, a roller carried by said lever andco-operating with said cam, a brake-shoe frictionally co-opcrating withsaid brike-lever, and a link pivotally connected to said roller-carryinglever and to said brake-shoe, and means for varying the position Olisaid shoe with rcspect to said brake-lever.

4. in leather stitching machine, the combination with a work support, ofa pivoted pi'esser foot cooperating therewith, a brakedever fixed tosaid foot, a cam, a lever fulcruined on a fixed p-ivot, a roller carriedby said lever and co-operating with said cam, a brake shoe cooperatingwith said brake-lever, a link pivotally connected to said lever and tosaid brakeshoe, and a supporting linkfor said brake-shoe pivotallyconnected to the last mentioned link.

5. In a leather stitching machine, the,

combination with a work support, of a pivoted presser foot cooperatingtherewith, a lever fixed to said footand having a convexed brakeengaging end, a cam having a notch formed in its periphery, a leverdisposed between said presser foot lever and sald cam and fulcrumed atits lower end on a fixed pivot, a roller carried by the npper end ofsaid lever for engagement with the periphery and notch of said cam, abrake-shoe having a concaved surface for engagement with the convexedbrake-engaging end of the presser foot lever, and a link having one endpivotally connected to the roller-carrying lever at a point above thefulcrum thereof and having its other end pivotally connected to saidbrake-shoe.

6. In a leather stitching machine, the

combination with a work #support, of a for releasing said locking meansduring the lesser portion of each cycle, said brakelever and saidbrake-shoe being respectively formed with convexed and. concavedengaging faces, and a supporting link for said brake-shoe pivotallyconnected to the last mentioned link.

7. In a leather stitching machine, the combination with a work support,Oili a pivoted presser foot co-operating therewith, a brake-lever fixedto said foot, a cam, means controlled by the cam including alink-supported brake-shoe co-operating with said brake-lever :forlockii'ig the foot against pivotal movements during the greater por tionof each cycle and for releasing said locking means duringthe lesserportion of each cycle, anda spring for yieldingly urging the presserfoot towards the work sup port.

8. In a leather stitching machine, the combination with a work support,of a pivoted presser toot co-operating therewith, a brake-lever fixed tosaid foot, a cam, a lever fulcrumed on a fixed pivot, a roller carriedby said lever and co-operating with said cam, a brake-shoe co-operatingwith said brake-lever, a link pivotally connected to said lever andtosaid brake-shoe, a mans ualmeans co-operating with said presser footlever for raising said foot, and a supporting link for the brake-shoepivotally connected to said manual means.

9. In a leather stitching machine, the combination with a work support,of a pivoted presser foot co-0perating therewith, a brake-lever fixed tosaid foot, a pin carried by said brake-lever, a cam, a lever i'ulcrumedon a fixed pivot, a roller carried by saidlever and co-operating withsaid cam, a brake-shoe co-operating with said brakelever, a linkpivotally connected to said lever and to said brake-shoe, a manuallyoperable lever fulcrumed on a fixed pivot for engagement with the pincarried by the brake-lever upon movement of said lever in one direction,an axially adjustable disk carried by said lever, and a link having oneend pivotally connected to said brake-shoe and the other end pivotallyconnected to said adjustable disk.

CHAR-LES F. MILLER.

